1. Field of Application
This invention relates to mechanisms for directing a stream of fluid from one level to another level in a body of the fluid or along the surface thereof; and more particularly to mechanisms for propelling the warmer water, located at the lower level in a body of water subject to cold and freezing temperatures, to move to the surface thereof to eliminate or minimize the formation of ice on said body of water or otherwise moving debris, oil slicks, or aerating water to encourage marine growth or circulate water to discourage marine growth.
2. Description of the Prior Art
Streams, rivers, lakes, ponds and similar bodies of water tend to freeze over in freezing weather. The ice thus formed not only impedes commercial shipping, and the use of pleasure craft, but also renders it impossible to park water craft, boats and ships at dockside, where ice will form easier and quicker in the still water, than in the channels kept open by moving ships and boats.
The tendency of the surface to freeze over, especially at marinas where pleasure craft are docked, has resulted in the damage of docks and pilings as well as the removal of many such craft from the water for land storage during cold winter seasons. This is an expensive operation requiring costly equipment and large quantities of land storage area. In addition, taking a boat out of the water and subsequent land storage is not always best for the boat. Alternatively, some marina's and docking areas utilize aeration systems to bubble or otherwise increase the air content of the water, or keep the water moving in attempts to eliminate ice once formed; or to prevent formation thereof. These systems, however, have proved costly and are not always as effective as is necessary.
One type of system for dealing with this problem utilizes equipment which is either partially or fully submerged in the body of water to move water from the lower levels thereof towards the upper level thereof. Such systems rely upon the theory that in such a body of water subject to cold or freezing temperature the water near or at the bottom is at a temperature warmer than freezing. When such warmer water is moved to the top of the body of water it will form a layer thereover and minimize or prevent the formation of ice on the body of water to damage to docks, pilings, and water craft. Thus, boats and ships can remain at dockside throughout the winter.
In systems such as the one shown in U.S. Pat. No. 2,827,268 granted to G. A. Staaf on Mar. 18, 1958 for Liquid Transporting Apparatus the use of a vertical tube, for directing the flow of lower level liquid to the surface of the body of liquid, not only constitutes an expensive structure but also can easily become an obstruction to the movement of ships and boats in the water.
Other available systems, such as shown in U.S. Pat. No. 3,109,288 granted to G. E. Gross on Nov. 5, 1963 for Oscillating and Aerating Ice and Water Control and in U.S. Pat. No. 4,104,526 granted on Mar. 29, 1977 to R. A. Cramer, Jr. for liquid Moving And Mixing Apparatus are not only quite complex in construction and operation but also have fan or propeller blades which are unshielded and can injure or kill fish and other water life.
Still other commercially available mechanisms such as shown in U.S. Pat. No. 3,083,538 granted to G. E. Gross on Apr. 2, 1963 for Apparatus For Maintaining A Body of Water Free of Ice, and like mechanisms, require either permanent or semi-permanent disposition of the device into the material at the waters bottom. As such there may be a tendency to suck up silt and dirt from the bottom beneath the body of water. This will cloud and dirty the water and foul the equipment. In addition, if the intake openings become clogged the mechanism will not perform its intended function.